Make sure no unibrow. And I guess use eyebrow pencil to lightly fill them in and make a shape? I know someone who's the same way, and it looks like that's what she does.

Are you allowed to cut them? Use an eyebrow brush to brush up the hairs and anything long, trim them w a scissor? That's what the eyebrows lady do wheN I get mine threaded after a long time. (I usually wait 3-4 weeks, but sometimes its been 6-8).